Gas protection device for laser welding or surface strengthening treatment

Abstract

The utility model relates to the technical field of laser welding or surface strengthening treatment, in particular to a gas protection device for laser welding or surface strengthening treatment, which comprises a shell, the shell comprises a first shell and a second shell, the first shell is embedded in the second shell, and the second shell is embedded in the second shell. The lower portion of the first shell and the lower portion of the second shell are each provided with a cone which shrinks from outside to inside. The upper end of the first shell and the upper end of the second shell are both connected with the sealing cover, and the gathering cavity is a cavity which is formed between the first shell and the second shell in a surrounding mode, is provided with a sealed top and an open bottom and is used for gathering protective gas; one end of the air inlet is connected with the side wall of the second shell; a plurality of gas through holes are formed in the sieve plate, a light through hole for laser to penetrate through is formed in the center of the sieve plate, the sieve plate is connected with the end of the first shell and the end of the second shell, and through the arrangement, the stability and the operation quality of the welding or surface strengthening treatment process can be effectively improved.

Description

Technical Field

[0001] The utility model relates to a gas protection device for laser welding or surface strengthening treatment, belonging to the technical field of laser welding or surface strengthening treatment. Background Art

[0002] Laser welding is an efficient and precise welding method and surface treatment method that uses a laser beam with a high energy density as a heat source. By irradiating the workpiece surface with a laser, the surface heat diffuses into the interior through heat conduction. By controlling parameters such as the width, energy, peak power, and repetition frequency of the laser pulse, the workpiece is melted to form a specific molten pool. In practical applications, it is common to supply a protective gas to the melting area to inhibit the pollution of the surrounding environmental gas to the molten pool and the nearby area, improve the coupling and transmission process of laser energy, and at the same time protect the molten pool metal from the invasion of harmful gases and prevent oxidation pollution.

[0003] Surface strengthening treatment is to use the transported gas to react metallurgically with the molten pool metal to generate a modified layer with high hardness and high wear resistance to improve the joint performance.

[0004] The above two methods are flexible, effective and practical. However, in the current prior art, in order to achieve a good protection effect, the gas protection device usually increases the supply rate of the protective gas, but this will lead to a significant increase in cost, and will also cause turbulence and disorderly flow of the protective gas due to the increase in the supply rate, resulting in the inability of the protective gas to be evenly output to the surface of the processed workpiece, seriously affecting the stability and quality of welding or surface strengthening treatment. In addition, there is also a problem in the prior art that air is involved from the top during the process of the protective gas gathering and flowing, reducing the purity and affecting the quality of welding or surface strengthening treatment. Secondly, because it takes a certain time for the molten pool to solidify after welding, as the welding device continues to move to the next position for welding, the welding molten pool will lose the protection of the protective gas during the cooling process, causing the outside air to contact the workpiece weld, resulting in oxidation of the workpiece weld and low quality of welding or surface strengthening treatment. Therefore, it is of great practical significance to research a new type of gas protection device. Content of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the utility model provides a gas protection device for laser welding or surface strengthening treatment.

[0006] The technical solution of the present utility model to solve the above technical problems is as follows: A gas protection device for laser welding or surface strengthening treatment, including a housing, the housing is a hollow jacket-like structure, including a first housing and a second housing, the first housing is embedded inside the second housing, a cavity for the laser to pass through is formed inside the first housing, and the lower parts of both the first housing and the second housing are provided with cones that contract from the outside to the inside; an aggregation cavity, the upper ends of both the first housing and the second housing are connected to a cover, and the aggregation cavity is a cavity formed by surrounding between the first housing and the second housing, sealed at the top and open at the bottom for aggregating the protective gas; an air inlet, one end of the air inlet is connected to the side wall of the second housing, and the other end is connected to a protective gas supply system; a sieve plate, a plurality of gas through holes are provided on the sieve plate and a light through hole for the laser to pass through is provided at the center, and the sieve plate is connected to the ends of the first housing and the second housing.

[0007] Further, the gas through holes of the sieve plate close to the light through hole are straight holes with axes parallel to the axis of the sieve plate, and the gas through holes close to the edge of the sieve plate are inclined holes with an included angle α1 between the axes of the parallel lines of the axis of the sieve plate.

[0008] Further, the range of the included angle α1 between the axis of the inclined hole and the parallel line of the axis of the sieve plate is 30 - 50 degrees.

[0009] Further, the axis of the inclined hole is arranged at the connection seam between the second housing and the sieve plate.

[0010] Further, the number of the straight holes is 2.5 - 3 times the number of the inclined holes.

[0011] Further, the range of the included angle α2 between the inclined plane of the lower part of the first housing and the axis of the first housing is 35 - 55 degrees.

[0012] Further, the included angle α3 between the inclined plane of the lower part of the second housing and its side wall is 1.0 - 1.2 times the included angle α4 between the inclined plane of the lower part of the first housing and its side wall.

[0013] Further, the inner diameter D1 of the second housing is 1.3 - 1.5 times the inner diameter D2 of the first housing.

[0014] Further, the protective gas is argon, helium, nitrogen or a mixed gas thereof.

[0015] Further, the transition parts of the lower cones of both the first housing and the second housing are provided with rounded corners.

[0016] The beneficial effects of the present utility model are:

[0017] (1) By setting the top of the agglomeration chamber as a sealed structure, compared with the top-open structure, this structure can avoid the problem of air being drawn in from the top during the agglomeration and flow of the protective gas, reducing the purity and affecting the quality of welding or surface strengthening treatment, and improving the stability and quality of the welding or surface strengthening treatment process;

[0018] (2) When the protective gas agglomerates to a certain pressure in the agglomeration chamber, the cones with inward contraction from the outside to the inside provided at the lower parts of the first shell and the second shell make the lower ring diameter of the agglomeration chamber smaller. When the protective gas flows through the lower part of the agglomeration chamber, it forms an acceleration, so that the protective gas has a good shooting speed when flowing out of the gas through-hole. And because when the protective gas is input into the agglomeration chamber through the air inlet, it will collide with the side wall of the agglomeration chamber, resulting in air flow disorder. By setting cones at the lower parts of the first shell and the second shell, the protective gas deflects in a certain direction when flowing through the lower part of the agglomeration chamber, which can play a role in guiding and stabilizing the flow of the protective gas, so that the protective gas can uniformly output to the surface of the workpiece along the conical side wall of the lower part of the agglomeration chamber through the gas through-hole, avoiding both the waste of the protective gas and the influence of the turbulent flow and chaotic flow of the protective gas output on the high-temperature molten pool, effectively protecting the high-temperature molten pool, and further improving the stability and quality of the welding or surface strengthening treatment process;

[0019] (3) By setting the lower part of the second shell as a cone, the structure is more compact, and it is more conducive to observing the welding or surface strengthening treatment effect of the workpiece during the welding or surface strengthening treatment process. Description of the Drawings

[0020] Figure 1 Structural schematic diagram of the gas protection device provided by the embodiment of the present invention;

[0021] Figure 2 Sectional view of the gas protection device provided by the embodiment of the present invention;

[0022] Figure 3 Another marked sectional view of the gas protection device provided by the embodiment of the present invention;

[0023] Figure 4 Enlarged view of part A of the gas protection device provided by the embodiment of the present invention.

[0024] Reference numerals: 1, first shell; 2, second shell; 3, agglomeration chamber; 4, air inlet; 5, sieve plate; 6, light through-hole; 7, straight hole; 8, inclined hole; 9, cover. Detailed Embodiment

[0025] The following will make a detailed description of the specific embodiments of the present invention. The present invention can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used are only for describing the specific embodiments and do not limit the present invention.

[0027] As Figure 1 shown, the present invention provides a gas protection device for laser welding or surface strengthening treatment, including a housing. The housing is of a hollow jacket-like structure, which includes a first housing 1 and a second housing 2. The first housing 1 is embedded inside the second housing 2, and the first housing 1 and the second housing 2 are coaxially arranged. A cavity for the laser to pass through is formed inside the first housing 1. Cones that contract from the outside to the inside are provided at the lower parts of both the first housing 1 and the second housing 2. It should be noted that in the present invention, the so-called lower part or lower end refers to the end close to the workpiece to be processed, and the so-called upper part or upper end refers to the end close to the laser generator; an aggregation chamber 3. The upper ends of both the first housing 1 and the second housing 2 are connected to the lower end of a cover 9, which can be integrally processed, or connected by welding, bonding or other means. The aggregation chamber 3 is the cavity between the first housing 1 and the second housing 2. The top of the aggregation chamber 3 is sealed and the bottom is open for gathering the protective gas; an air inlet 4. One end of the air inlet 4 is connected to the side wall of the second housing 2, and the two can be an integral structure formed by processing, or welded. A sieve plate 5 is provided with a number of gas through holes for the flow of the protective gas. A light through hole 6 for the laser to pass through is coaxially arranged at the center of the sieve plate 5. The sieve plate 5 is connected to the ends of the first housing 1 and the second housing 2. The end of the first housing 1 is connected to the sieve plate 5 around the edge of the light through hole 6.

[0028] First, by setting the top of the agglomeration chamber 3 as a sealed structure, compared with the top-open structure, this structure can avoid the problem of air being involved from the top during the agglomeration and flow of the protective gas, reducing the purity and affecting the quality of welding or surface strengthening treatment, and improving the stability and quality of the welding or surface strengthening treatment process. Secondly, when the protective gas agglomerates to a certain pressure in the agglomeration chamber 3, the cones arranged from the outside to the inside at the lower parts of the first shell 1 and the second shell 2 make the lower ring diameter of the agglomeration chamber 3 smaller. When the protective gas flows through the lower part of the agglomeration chamber 3, acceleration is formed, so that the protective gas has a good shooting speed when flowing out of the gas through-hole. And because when the protective gas is input into the agglomeration chamber 3 through the air inlet 4, it will collide with the side wall of the agglomeration chamber 3, resulting in turbulence and chaotic flow of the protective gas. By arranging cones at the lower parts of the first shell 1 and the second shell 2, the protective gas deflects in a certain direction when flowing through the lower part of the agglomeration chamber 3, which can play a role in guiding and stabilizing the flow of the protective gas, so that the protective gas can uniformly output to the surface of the workpiece along the conical side wall of the lower part of the agglomeration chamber 3 through the gas through-hole, avoiding both the waste of the protective gas and the influence of the turbulence and chaotic flow of the protective gas output on the high-temperature molten pool, and effectively protecting the high-temperature molten pool, further improving the stability and quality of the welding or surface strengthening treatment process. Finally, by setting the lower part of the second shell 2 as a cone, the structure is more compact, and during the welding or surface strengthening treatment process, it is more conducive to observing the welding or surface strengthening treatment effect of the workpiece.

[0029] Specifically, the gas through-holes on the side of the sieve plate 5 close to the light-transmitting hole 6 are straight holes 7 with axes parallel to the axis of the sieve plate 5, and the gas through-holes on the side close to the edge of the sieve plate 5 are inclined holes 8 with an included angle α1 between the axes of the inclined holes and the parallel lines of the axis of the sieve plate 5. Through the above settings, first, the straight holes 7 can maintain good protection for the high-temperature molten pool during welding or surface strengthening treatment. The inclined holes 8 are used to expand the protection range of the shielding gas for the molten pool. Specifically, because it takes a certain amount of time for the molten pool to solidify after welding or surface strengthening treatment, as the welding or surface strengthening treatment continues for the next position, it will cause the high-temperature molten pool to lose the protection of the shielding gas during the cooling process, allowing the outside air to come into contact with the molten pool of the workpiece to be welded, resulting in oxidation at the weld of the workpiece to be welded and low-quality welding or surface strengthening treatment. By setting the straight holes 7 and the inclined holes 8, it is possible to protect the high-temperature molten pool during welding or surface strengthening treatment and continuously protect the high-temperature molten pool during the cooling process, playing a role of delayed protection. Second, during the movement of the welding torch, by setting the inclined holes 8, it is possible to blow out the shielding gas to clean the impurities at the position to be processed on the surface of the workpiece, preventing impurities from entering the molten pool during welding or surface strengthening treatment and affecting the quality, further ensuring the quality of welding or surface strengthening treatment. On the premise of ensuring the overall compact structure, diverse functions are realized, effectively reducing the occurrence of defective parts during welding or surface strengthening treatment; preferably, the range of the included angle α1 between the axis of the inclined hole 8 and the parallel line of the axis of the sieve plate 5 is 30 - 50 degrees. When the included angle α1 is less than 30 degrees, although it is possible to clean the impurities at the position to be processed during the movement of the welding torch, due to the small delayed protection area, there will still be a certain degree of oxidation phenomenon during the cooling process of the high-temperature molten pool. When the included angle α1 is greater than 50 degrees, the protection during the cooling process of the high-temperature molten pool is strengthened, avoiding the oxidation of the high-temperature molten pool. However, the cleaning process is relatively early, causing the cleaned position to be processed to be contaminated by the soot or splashed impurities generated at the processing position, resulting in impurities entering the high-temperature molten pool during the subsequent welding or surface strengthening treatment and affecting the quality, as well as wasting the shielding gas. Only when the included angle α1 ranges from 30 to 50 degrees can the oxidation during the cooling process of the high-temperature molten pool be avoided and the entry of impurities into the high-temperature molten pool during welding or surface strengthening treatment be prevented from affecting the quality.

[0030] Specifically, the number of the straight holes 7 is 2.5 - 3 times that of the inclined holes 8. If the number of the straight holes 7 is less than 2.5 times that of the inclined holes 8, the protection of the machining position will be weakened, resulting in more contact between the high-temperature molten pool and the air, affecting the quality of welding or surface strengthening treatment. Moreover, the plasma generated during the operation cannot be well dispersed, leading to a shallower welding depth of the workpiece and further affecting the quality of welding or surface strengthening treatment. If the number of the straight holes 7 is greater than 3 times that of the inclined holes 8, although the operation quality in the machining area is guaranteed at this time, the delayed protection area is small, and a certain degree of oxidation will still occur during the cooling process of the high-temperature molten pool. Preferably, the axis of the inclined hole 8 is arranged at the joint between the second housing 2 and the sieve plate 5. Through this setting, the axial length of the inclined hole 8 can be increased, that is, the channel length of the shielding gas can be increased, and the shielding gas can be further accelerated when passing through, improving the delayed protection ability and the impurity removal ability.

[0031] Specifically, the included angle α2 between the lower conical slope of the first housing 1 and the axis of the first housing 1 ranges from 35° to 55°. If the included angle α2 is less than 35°, the turning and guiding flow and the flow stabilizing effect of the lower conical part of the first housing 1 on the shielding gas become poor, making the shielding gas unable to be evenly output to the surface of the workpiece, resulting in an impact on the high-temperature molten pool due to the turbulent flow and chaotic flow during the output of the shielding gas, affecting the stability and quality of the welding or surface strengthening treatment process. If the included angle α2 is greater than 55°, on the premise of ensuring the guiding flow and flow stabilizing effect on the shielding gas, that is, on the premise of ensuring the length of the lower conical part of the first housing 1, it is necessary to increase the radial width of the first housing 1, resulting in a larger overall size and lack of compactness, which not only increases the manufacturing cost but also is not conducive to observing the welding or surface strengthening treatment effect of the workpiece to be processed.

[0032] Specifically, the included angle α3 between the lower conical slope of the second housing 2 and its side wall is 1.0 - 1.2 times the included angle α4 between the lower conical slope of the first housing 1 and its side wall. If the included angle α3 is less than 1.0 times the included angle α4, the lower conical part of the second housing 2 shrinks too much inward, resulting in too small a range for connecting the sieve plate 5 to output the shielding gas, leading to a weakened protection intensity for the high-temperature molten pool and a reduced protection range for the high-temperature molten pool, seriously affecting the quality of welding or surface strengthening treatment. If the included angle α3 is greater than 1.2 times the included angle α4, although the protection range becomes larger, the guiding flow effect of the shielding gas becomes poor and the acceleration effect when the shielding gas flows through the lower part of the aggregation cavity 3 becomes poor, making the shielding gas not have a good shooting speed when flowing out of the gas through-hole, and also resulting in a weakened protection for the high-temperature molten pool of the workpiece to be processed and the molten pool and its vicinity during the cooling process, which is not conducive to the stability and quality during the welding or surface strengthening treatment process.

[0033] Specifically, the inner diameter D1 of the second housing 2 is 1.3 - 1.5 times the inner diameter D2 of the first housing 1. If the inner diameter D1 of the second housing 2 is less than 1.3 times the inner diameter D2 of the first housing 1, at this time, because the gap between the side walls of the two housings is too small, it will cause the collision between the shielding gas and the side wall of the second housing 2 to intensify during the process of the shielding gas entering the agglomeration chamber 3 through the air inlet 4, resulting in serious gas turbulence and chaotic flow phenomena. Even after the diversion and flow stabilization of the shielding gas by the lower part of the agglomeration chamber 3, the turbulence and chaotic flow of the shielding gas still cannot be solved, making the shielding gas unable to be evenly output to the surface of the workpiece, resulting in the influence of the turbulence and chaotic flow during the output of the shielding gas on the high-temperature molten pool, affecting the stability and quality of the welding or surface strengthening process; if the inner diameter D1 of the second housing 2 is greater than 1.5 times the inner diameter D2 of the first housing 1, it will cause the overall size to become larger and not compact, which not only increases the manufacturing cost but also is not conducive to observing the welding or surface strengthening treatment effect of the workpiece. Only when the inner diameter D1 of the second housing 2 is 1.3 - 1.5 times the inner diameter D2 of the first housing 1 can the overall size be coordinated and the stability and quality of the welding or surface strengthening process be ensured.

[0034] Specifically, the shielding gas is an inert gas with high stability and not easily reacting with other substances, preferably argon, helium, nitrogen, or a mixture thereof.

[0035] Specifically, the transition at the lower cone of the first housing 1 and the transition at the lower cone of the second housing 2 are set as rounded corners. Through the above settings, the occurrence of turbulence and chaotic flow during the flow of the shielding gas in the agglomeration chamber 3 can be further avoided, and the stability and quality of the welding or surface strengthening process can be further improved.

[0036] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, all possible combinations of the technical features in the above-described embodiments are not exhaustively listed. However, as long as the combinations of these technical features do not conflict, they should be considered to be within the scope described in this specification.

[0037] For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. The protection scope of the present invention is subject to the appended claims.

Claims

1. A gas protection device for laser welding or surface strengthening treatment, characterized in that: include: A shell, the shell is a hollow jacket-like structure, comprising a first shell and a second shell, the first shell is embedded in the second shell, a cavity for laser to pass through is formed inside the first shell, and the lower part of the first shell and the lower part of the second shell are both configured as cones that contract from outside to inside; A gathering cavity, wherein the upper ends of the first shell and the second shell are both connected to the cover, and the gathering cavity is a cavity formed between the first shell and the second shell and having a top sealed and a bottom open for gathering protective gas; An air inlet, one end of which is connected to the side wall of the second shell, and the other end of which is connected to the protective gas supply system; The sieve plate is provided with a plurality of gas through holes and a light through hole for laser to pass through is arranged in the center, and the sieve plate is connected to the first shell end and the second shell end.

2. A gas protection device for laser welding or surface strengthening treatment according to claim 1, characterized in that: The gas through holes on the sieve plate close to the light through holes are straight holes whose axes are parallel to the axis of the sieve plate, and the gas through holes close to the edge of the sieve plate are inclined holes whose axes have an angle α1 with the parallel line of the axis of the sieve plate.

3. A gas protection device for laser welding or surface strengthening treatment according to claim 2, characterized in that: The angle α1 between the axis of the inclined hole and the parallel line of the axis of the sieve plate is in the range of 30-50 degrees.

4. A gas protection device for laser welding or surface strengthening treatment according to claim 2, characterized in that: The axis of the inclined hole is arranged at the connection seam between the second shell and the sieve plate.

5. A gas protection device for laser welding or surface strengthening treatment according to claim 2, characterized in that: The number of the straight holes is 2.5-3 times the number of the inclined holes.

6. The gas protection device for laser welding or surface strengthening treatment according to claim 1, characterized in that: The included angle α2 between the inclined surface of the cone at the lower part of the first shell and the axis of the first shell is in the range of 35-45 degrees.

7. A gas protection device for laser welding or surface strengthening treatment according to claim 6, characterized in that: The included angle α3 between the lower cone slope of the second shell and its side wall is 1.0-1.2 times the included angle α4 between the lower cone slope of the first shell and its side wall.

8. The gas protection device for laser welding or surface strengthening treatment according to claim 1, characterized in that: The inner diameter D1 of the second shell is 1.3-1.5 times the inner diameter D2 of the first shell.

9. The gas protection device for laser welding or surface strengthening treatment according to claim 1, characterized in that: The protective gas is argon, helium, nitrogen or a mixture thereof.

10. The gas protection device for laser welding or surface strengthening treatment according to claim 1, characterized in that: The transition point of the cone at the lower part of the first shell is set as a rounded corner.

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